This invention relates to a computer system having a storage system and a management computer, and more particularly, to a technique of balancing a load of a parity group.
A recent improvement in host computer performance and transmission speed of Internet lines has caused an increase in an amount of data handled by a host computer, which in turn increases access to a storage system where data is stored.
In most cases, logical volumes in a storage system are accessed unevenly and the load of a parity group is accordingly unbalanced. As a solution to the unbalanced load of a parity group, a migration technique is known which moves a logical volume from one storage system to another.
JP 2001-337790 A discloses a technique in which a data migration instruction is issued when a utilization ratio of a logical volume in a storage system exceeds a threshold, thereby moving data out of this logical volume and balancing the load of a parity group.